It’s a pretty huge leap of logic to assume that since a cement company is involved they are ballasting the ships. In order to complete the LHD integration Williamstown Dockyard required a “facility readiness program” which included work on mooring and access, wharf services, heavy lift preparation and a stand-by crew facility. All of these works would require concrete.
Royal Australian Navy Discussions and Updates
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Worst job I ever did was removing lead ballast ingots from the'Flamingo Bay", an old ice breaking tug turned marine reaseach vessel. we did it by hand. concrete would be a night mare, being much bulkyier(is that a word? Sorry) than lead.
/mythbusters - "shake and bake" /smirk
The_Wrecker
New Member
Hi all. As as avid reader but seldom poster, I have a question regarding the Hobart class ships. I was reading wiki ( I know, not the best source of info) and noticed the Hobart class are slated to have 2x LM2500 gas turbines installed. According to the article they are rated at 23,500hp each. I found this interesting as the Anzac class has one LM2500 rated at 30,000hp. I also read that the LM2500 is available in different versions up to 47,000ish hp. My question to those in the know is: why install such a de-tuned version of the turbine? Is it purely a case of endurance? Or are there many different sizes of turbine in the LM2500 range of which not all would fit the Hobart hull form? Thanks in advance for any info. Sorry if the format of my post is not great as I am using an iPhone.
The answer is quite simple, the Hobarts are baselined on the Spanish F-104 with some changes incorporated from the F-105 and due to specific RAN / Aust Govt requirements. Long story short, its what Spain specified in the F-104 so we got the same.
On the LM2500 the physical size of the different rated models is the same it is the power output that differ for different applications and I should add costs, i.e. the higher rated units have digital control etc.
The_Wrecker
New Member
Thanks for the reply Volkodav.
Your reasoning behind the issue makes a lot of sense. I guess it all comes down to risk. If elements are swapped out from the original design no doubt it has a knock on effect to the complete platform in many more ways than I can ever imagine.
My original thinking was that the first f-100 was designed many years ago now and wouldn't it be prudent to leverage off the evolution in turbine tech?
To be honest I have not been able to find any specs on the 7LM2500-SA-MLG38 gas turbines being fitted but was able to download a GE spec sheet on the LM2500 (I have a link but am a few posts short of being able to add it....)
none of which fit the stated model being installed. Maybe it's a legacy version and we are getting them cheap
At the end of the day I was just pondering as to whether we were getting the best bang for our buck...? Based on the governments aversion to risk...I guess we are..lol
Cheers.
Gordon Branch
New Member
The Coles Review into Collins Class operations has been released.
Reviews of Australian submarines released - Department of Defence
Some of the links out of the above page are interesting. I found the recommended availability levels most interesting of all.
"The Report recommends the target levels of availability for a fleet of six submarines should be:
Two submarines available 100 per cent of the time;
Three submarines available 90 per cent of the time; and
Four submarines available 50 per cent of the time."
This probably won't get aired in the general media.
Reviews of Australian submarines released - Department of Defence
Some of the links out of the above page are interesting. I found the recommended availability levels most interesting of all.
"The Report recommends the target levels of availability for a fleet of six submarines should be:
Two submarines available 100 per cent of the time;
Three submarines available 90 per cent of the time; and
Four submarines available 50 per cent of the time."
This probably won't get aired in the general media.
On the topic of gas turbines in Australian warships , some questions for the professionals:
How often and under what circumstances do RAN ships run at full speed with all engines?
What is the max speed gained by adding the gas turbine?.
What is seen to be the main advantage of adding gas turbines,total speed or quicker acceleration?
Are these advantages worth the added cost of fitting and maintaining the gas turbines.
How often and under what circumstances do RAN ships run at full speed with all engines?
What is the max speed gained by adding the gas turbine?.
What is seen to be the main advantage of adding gas turbines,total speed or quicker acceleration?
Are these advantages worth the added cost of fitting and maintaining the gas turbines.
(Can only speak in terms of use in the RN)
AFAIK the rule of thumb is that in a warship, diesel engines are used for range + fuel efficiency and quieter tasks like elements of ASW to reduce their acoustic signature whereas GTs are there when the warship needs to 'sprint' at high speed and fuel efficiency is somewhere further down on the agenda.
We (FFH) only run at full speed during trials at the present.
Most of the time we run on eco mode, in order to save fuel.
Yep and if you are made enough to use concrete as ballast you can add hull integrity issues as moisture will eventually get between the concrete and steel.
In most large ships stability is "built" in though design an equipment location as well as moveable ballast (liquids).
the road runner
Active Member
BAE have a video showing the last block for the LHD put into place.
[nomedia="http://www.youtube.com/watch?v=Kaao_1ehONc"]BAE Systems Williamstown - Final Block Heavy Lift - LHD Superstructure - YouTube[/nomedia]
That section must be a few hundred odd ton's being craned into position.Have to say its impressive seeing sections like that put into place.
Anyone know how heavy that section would be?
Also saw the Chinese navy is in town.I went passed Garden island and one thing that struck me was how rusted the bottom section of their frigates looked??
Will take some pics tomorrow
[nomedia="http://www.youtube.com/watch?v=Kaao_1ehONc"]BAE Systems Williamstown - Final Block Heavy Lift - LHD Superstructure - YouTube[/nomedia]
That section must be a few hundred odd ton's being craned into position.Have to say its impressive seeing sections like that put into place.
Anyone know how heavy that section would be?
Also saw the Chinese navy is in town.I went passed Garden island and one thing that struck me was how rusted the bottom section of their frigates looked??
Will take some pics tomorrow
t68
Well-Known Member
Those time lapse videos make thing look easy, but how long in the planning would that have taken , I have been watching the RN new carriers being built and it still amazes me that that amount of steel can float.
Gordon Branch
New Member
The rust is probably due to the fact these ships have been on anti-piracy duties in the Gulf of Aden. They have been on active service and are their way home.
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Quite a few problems with suppliers, and confusion with standing orders, and thats just the majors. The patrol boats you should be well aware of as you sail past of a night.Thats a change, you can usually tell the RAN ships apart, not from their colour but from their disgraceful ship side presentation.
I think I've commented on this before, so enough
The chinese are much like the japanese, in that their anti-piracy is more escorts of convoys with a chinese flag and anyone who can keep up. Not much on the russians though, who patrol back and forth lit up like a christmas tree waiting to be attacked...
She is looking good, still disappointed that it looks like we won't be retaining the RAS station as on the JC1. A capability that I would have thought would be very handy for the RAN
P.S. has anyone figured out what the big box in front of and below the bridge was for ?
John Newman
The Bunker Group
I think it has to do with refuelling, I put up a post a few weeks ago (#9983) with some photos, I'll link them again.She is looking good, still disappointed that it looks like we won't be retaining the RAS station as on the JC1. A capability that I would have thought would be very handy for the RAN
P.S. has anyone figured out what the big box in front of and below the bridge was for ?
If you look at the two photos, taken from basically the same position on the flight deck of the two ships.
On JC1 it appears that, lower down and directly onto the face of the bridge structure, a "swing" arm is mounted which appears to be associated with the refuelling at sea equipment below and to the left of it.
On Canberra, the fittings in the four corners of the protrusion look the same as the fittings that attach the swing arm to JC1.
With the front of the Island sloping backwards and to keep the same vertical alignment, that probably accounts for the protrusion.
I might be right or wrong, don't know, but that's how it looks to me.
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I'm sure you're correct. My theory about a lifting bracket was bs and I don't think AG's ae brackets hold water either.
Cheers
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John Newman
The Bunker Group
Again I don't know if I'm right or wrong, but it does appear likely when comparing the two photos.
With JC1 being first of class there was bound to be changes made for follow on ships, apart from specific Australian modifications to the original design.
If it is what I think it is, maybe there was an issue with the arm being mounted down too low on JC1, maybe the mount on JC1 might change in the future too.
The protrusion on Canberra looks bloody ugly, but obviously its been positioned there for a reason.
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